Weird cursor in Firefox

All of a sudden, I’ve got a blinking cursor in Firefox, as if I were in a text document. It appears wherever I click, and using the up and down arrows move it on the page rather than scrolling on the page itself.

I assume my kitten got to the keyboard and changed something. Anyone know how to turn it off?

You’ve got Firefox in Caret Browsing mode. It’s useful if you like selecting text with your keyboard, and for other stuff I can’t think of right now.

Hit F7 a few times and it’ll disappear. You can also check out this awesome page with keyboard shortcuts for Firefox, IE and Opera in both Windows and Linux OSs.